Literature Searching and Reviews

The topic or research question is the focal point of the literature search. The question should be as focused and structured as possible. Ask only a few, and possibly only one, question and focus on what you want as answers. A structured question makes it easier to divide the search into blocks and then conduct a systematic literature search.

There are models (conceptualization models) that can be used to formulate research questions. The models contribute to structure and definition. The most appropriate model to use depends on the topic and can assist in the development of a protocol

A model or protocol may not be relevant, so if you are a student, consult your supervisor about this.
In the Humanities (especially the classical disciplines) and Social Sciences, protocols or models are rarely used, as is the case in e.g. Health Sciences. But it is still important that you try to structure your search. It should match your problem statement and by documenting your work in designing the search and search blocks, you also make it easier to recreate or repeat your searches. It's also important to remember that the literature search is an iterative process where the results from the first search can influence how you adapt your keywords and then proceed with a new search - this will also sharpen your problem statement and make your project easier to complete. This can be done by identifying the exact core concepts in your field using the databases' controlled keywords, including the right ones and excluding the irrelevant ones.

Examples on conceptualization models

CIMO: is a qualitative reserach approach and is used to understand complex social and organizational phenomena – the way they oxxur and change over time. C (Context), I (Intervention), M (Mechanism), O (Outcome). (Xia, 2000)

CoCoPOP: can be used when formulating a research question related to the incidence or prevalence of a disease, symptom or health condition Co (Condition), Co (Context) POP (Population). The model describes four elements of a focused clinical question. (Munn, 2015). 

PCC: recommended in JBI Manual for Evidence Synthesis, when a research question must be formulated for a scoping review:
(P) Population, (C) Concept and (C) Context.

PEO: P (Population), E (Exposure) and O (Outcome) can be used for topics that deal with the relationship between exposure and a health outcome. (Bettany-Saltikov, 2016)

PICO: P (Patient / Problem / Population), I (Intervention), C (Comparator) and O (Outcome) (Eriksen, 2018 og McKenzie, 2023)
Use a form to Formulate your research question and break down your search in to blocks.
PICO may be expanded to PICOT: T (Timing / Types of studies) or PICOS if S (Setting) is important. 

PICo: is usefull when a certain phenomenon is interesting in relation to a patient group, possibly in a specific context:
P (Patient/problem/population), I (Phenomenon of Interest) and Co (Context). Use a form to Formulate your research question and break down your search in to blocks. (Review Question, 2020)

PIRD: may be used when formulating a research question regarding the accuracy of diagnostic tests (diagnostic test accuracy). P (Population), I (Index test), R (Reference test), D (Diagnosis of interest). (Campbell, 2015)

SPICE: is: S (Setting), P (Population), I (Intervention), C (Comparison) and E (Evaluation) (Booth, 2006)

SPIDER: is another model customized qualitative questions: S (Sample), PI (Phenomenon of Interest), D (Design), E (Evaluation) and R (Research type). (Cooke, 2012)

Bettany-Saltikov, J., & McSherry, R. (2016). How to do a systematic literature review in nursing : a step-by-step guide (Second edition ed.). McGraw Hill Open University Press. 

Booth, A., & Cleyle, S. (2006). Clear and present questions: formulating questions for evidence based practice. Library Hi Tech, 24(3), 355-368. https://doi.org/10.1108/07378830610692127 

Campbell, J. M., Klugar, M., Ding, S., Carmody, D. P., Hakonsen, S. J., Jadotte, Y. T., White, S., & Munn, Z. (2015). Diagnostic test accuracy: methods for systematic review and meta-analysis. Int J Evid Based Healthc, 13(3), 154-162. https://doi.org/10.1097/xeb.0000000000000061

Cooke, A., Smith, D., & Booth, A. (2012). Beyond PICO: the SPIDER tool for qualitative evidence synthesis. Qualitative Health Research, 22(10), 1435-1443. https://doi.org/10.1177/1049732312452938

Eriksen, M. B., & Frandsen, T. F. (2018). The impact of patient, intervention, comparison, outcome (PICO) as a search strategy tool on literature search quality: a systematic review. Journal of the Medical Library Association, 106(4), 420-431. https://doi.org/10.5195/jmla.2018.345 

McKenzie, J. E., Brennan, S. E., Ryan, R. E., Thomson, H. J., Johnston, R. V., & Thomas, J. (2023). Chapter 3: Defining the criteria for including studies and how they will be grouped for the synthesis. In J. P. T. Higgins, J. Thomas, J. Chandler, M. Cumpston, T. Li, M. J. Page, & V. A. Welch (Eds.), Cochrane handbook for systematic reviews of interventions (6.4. ed.). Wiley-Blackwell. https://training.cochrane.org/handbook/current/chapter-03 
Munn, Z., Moola, S., Lisy, K., Riitano, D., & Tufanaru, C. (2015). Methodological guidance for systematic reviews of observational epidemiological studies reporting prevalence and cumulative incidence data. Int J Evid Based Healthc, 13(3), 147-153. https://doi.org/10.1097/xeb.0000000000000054 

Review question 2.6.3. (2020). In Aromataris. E. & Munn Z (Eds.), JBI Manual for Evidence Synthesis. JBI. https://jbi-global-wiki.refined.site/space/MANUAL/4688141/2.6.2+Review+question

Xia, Yan, Anthony Tung Shuen Ho, and YuCheng Zhang. (2000). “Cimo-component integration model.” Proceedings Seventh Asia-Pacific Software Engeering Conference. APSEC 2000. IEEE, 2000.